[FFmpeg-devel] [PATCH v2] avformat/hls: clean up duplicate option fields

Richard Shaffer rshaffer at tunein.com
Mon Apr 16 22:02:11 EEST 2018


On Fri, Apr 13, 2018 at 5:14 PM, <rshaffer at tunein.com> wrote:

> From: Richard Shaffer <rshaffer at tunein.com>
>
> The HLSContext struct contains fields which duplicate the data stored in
> the
> avio_opts field. This change removes those fields in favor of avio_opts,
> and
> updates the code accordingly.
> ---
> The original patch caused the buffer pointed to by new_cookies in open_url
> to be
> leaked. The only thing that buffer is used for is to store the value until
> it
> can be passed to av_dict_set. To fix the leak, v2 of the patch simply calls
> av_dict_set with the AV_DICT_DONT_STRDUP_VAL flag, so that the dictionary
> takes
> ownership of the memory instead of copying it again.
>
>  libavformat/hls.c | 74 +++++++-----------------------
> -------------------------
>  1 file changed, 9 insertions(+), 65 deletions(-)
>
> diff --git a/libavformat/hls.c b/libavformat/hls.c
> index 1257cd101c..d6158c0ada 100644
> --- a/libavformat/hls.c
> +++ b/libavformat/hls.c
> @@ -202,11 +202,6 @@ typedef struct HLSContext {
>      int64_t first_timestamp;
>      int64_t cur_timestamp;
>      AVIOInterruptCB *interrupt_callback;
> -    char *referer;                       ///< holds HTTP referer set as
> an AVOption to the HTTP protocol context
> -    char *user_agent;                    ///< holds HTTP user agent set
> as an AVOption to the HTTP protocol context
> -    char *cookies;                       ///< holds HTTP cookie values
> set in either the initial response or as an AVOption to the HTTP protocol
> context
> -    char *headers;                       ///< holds HTTP headers set as
> an AVOption to the HTTP protocol context
> -    char *http_proxy;                    ///< holds the address of the
> HTTP proxy server
>      AVDictionary *avio_opts;
>      int strict_std_compliance;
>      char *allowed_extensions;
> @@ -267,10 +262,6 @@ static void free_playlist_list(HLSContext *c)
>          av_free(pls);
>      }
>      av_freep(&c->playlists);
> -    av_freep(&c->cookies);
> -    av_freep(&c->user_agent);
> -    av_freep(&c->headers);
> -    av_freep(&c->http_proxy);
>      c->n_playlists = 0;
>  }
>
> @@ -593,14 +584,6 @@ static int ensure_playlist(HLSContext *c, struct
> playlist **pls, const char *url
>      return 0;
>  }
>
> -static void update_options(char **dest, const char *name, void *src)
> -{
> -    av_freep(dest);
> -    av_opt_get(src, name, AV_OPT_SEARCH_CHILDREN, (uint8_t**)dest);
> -    if (*dest && !strlen(*dest))
> -        av_freep(dest);
> -}
> -
>  static int open_url_keepalive(AVFormatContext *s, AVIOContext **pb,
>                                const char *url)
>  {
> @@ -684,12 +667,8 @@ static int open_url(AVFormatContext *s, AVIOContext
> **pb, const char *url,
>          if (!(s->flags & AVFMT_FLAG_CUSTOM_IO))
>              av_opt_get(*pb, "cookies", AV_OPT_SEARCH_CHILDREN,
> (uint8_t**)&new_cookies);
>
> -        if (new_cookies) {
> -            av_free(c->cookies);
> -            c->cookies = new_cookies;
> -        }
> -
> -        av_dict_set(&opts, "cookies", c->cookies, 0);
> +        if (new_cookies)
> +            av_dict_set(&opts, "cookies", new_cookies,
> AV_DICT_DONT_STRDUP_VAL);
>      }
>
>      av_dict_free(&tmp);
> @@ -736,14 +715,7 @@ static int parse_playlist(HLSContext *c, const char
> *url,
>
>      if (!in) {
>          AVDictionary *opts = NULL;
> -        /* Some HLS servers don't like being sent the range header */
> -        av_dict_set(&opts, "seekable", "0", 0);
> -
> -        // broker prior HTTP options that should be consistent across
> requests
> -        av_dict_set(&opts, "user_agent", c->user_agent, 0);
> -        av_dict_set(&opts, "cookies", c->cookies, 0);
> -        av_dict_set(&opts, "headers", c->headers, 0);
> -        av_dict_set(&opts, "http_proxy", c->http_proxy, 0);
> +        av_dict_copy(&opts, c->avio_opts, 0);
>
>          if (c->http_persistent)
>              av_dict_set(&opts, "multiple_requests", "1", 0);
> @@ -1169,14 +1141,6 @@ static int open_input(HLSContext *c, struct
> playlist *pls, struct segment *seg,
>      int ret;
>      int is_http = 0;
>
> -    // broker prior HTTP options that should be consistent across requests
> -    av_dict_set(&opts, "user_agent", c->user_agent, 0);
> -    av_dict_set(&opts, "referer", c->referer, 0);
> -    av_dict_set(&opts, "cookies", c->cookies, 0);
> -    av_dict_set(&opts, "headers", c->headers, 0);
> -    av_dict_set(&opts, "http_proxy", c->http_proxy, 0);
> -    av_dict_set(&opts, "seekable", "0", 0);
> -
>      if (c->http_persistent)
>          av_dict_set(&opts, "multiple_requests", "1", 0);
>
> @@ -1193,7 +1157,6 @@ static int open_input(HLSContext *c, struct playlist
> *pls, struct segment *seg,
>      if (seg->key_type == KEY_NONE) {
>          ret = open_url(pls->parent, in, seg->url, c->avio_opts, opts,
> &is_http);
>      } else if (seg->key_type == KEY_AES_128) {
> -        AVDictionary *opts2 = NULL;
>          char iv[33], key[33], url[MAX_URL_SIZE];
>          if (strcmp(seg->key, pls->key_url)) {
>              AVIOContext *pb = NULL;
> @@ -1218,14 +1181,10 @@ static int open_input(HLSContext *c, struct
> playlist *pls, struct segment *seg,
>          else
>              snprintf(url, sizeof(url), "crypto:%s", seg->url);
>
> -        av_dict_copy(&opts2, c->avio_opts, 0);
> -        av_dict_set(&opts2, "key", key, 0);
> -        av_dict_set(&opts2, "iv", iv, 0);
> -
> -        ret = open_url(pls->parent, in, url, opts2, opts, &is_http);
> -
> -        av_dict_free(&opts2);
> +        av_dict_set(&opts, "key", key, 0);
> +        av_dict_set(&opts, "iv", iv, 0);
>
> +        ret = open_url(pls->parent, in, url, c->avio_opts, opts,
> &is_http);
>          if (ret < 0) {
>              goto cleanup;
>          }
> @@ -1781,7 +1740,6 @@ static int hls_close(AVFormatContext *s)
>
>  static int hls_read_header(AVFormatContext *s)
>  {
> -    void *u = (s->flags & AVFMT_FLAG_CUSTOM_IO) ? NULL : s->pb;
>      HLSContext *c = s->priv_data;
>      int ret = 0, i;
>      int highest_cur_seq_no = 0;
> @@ -1794,29 +1752,15 @@ static int hls_read_header(AVFormatContext *s)
>      c->first_timestamp = AV_NOPTS_VALUE;
>      c->cur_timestamp = AV_NOPTS_VALUE;
>
> -    if (u) {
> -        // get the previous user agent & set back to null if string size
> is zero
> -        update_options(&c->user_agent, "user_agent", u);
> -
> -        // get the previous cookies & set back to null if string size is
> zero
> -        update_options(&c->cookies, "cookies", u);
> -
> -        // get the previous headers & set back to null if string size is
> zero
> -        update_options(&c->headers, "headers", u);
> -
> -        // get the previous http proxt & set back to null if string size
> is zero
> -        update_options(&c->http_proxy, "http_proxy", u);
> -    }
> -
> -    if ((ret = parse_playlist(c, s->url, NULL, s->pb)) < 0)
> -        goto fail;
> -
>      if ((ret = save_avio_options(s)) < 0)
>          goto fail;
>
>      /* Some HLS servers don't like being sent the range header */
>      av_dict_set(&c->avio_opts, "seekable", "0", 0);
>
> +    if ((ret = parse_playlist(c, s->url, NULL, s->pb)) < 0)
> +        goto fail;
> +
>      if (c->n_variants == 0) {
>          av_log(NULL, AV_LOG_WARNING, "Empty playlist\n");
>          ret = AVERROR_EOF;
> --
> 2.15.1 (Apple Git-101)
>
>
Just wanted to send a reminder about this patch. The original version was
sent about a week ago. If anyone has time to review and either comment or
merge, that would be really great.

-Richard


More information about the ffmpeg-devel mailing list